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3 years ago

A compound in a copper ore has the following percentage composition by mass:

1 answer:

6 0

1) since we are given percentages, we can assume we have 100 grams of the molecule.

55.6 % Cu ----> 55.6 grams Cu
16.4 % Fe------> 16.4 grams Fe
28.0% S--------> 28.0 grams S

2) convert each gram to moles using the molar masses given

$55.6 g Cu \frac{1 mol}{63.5 g} = 0.876 mol Cu$
$16.4 g Fe \frac{1 mol}{56.0 g} = 0.293 mol Fe$
$28.0 gS \frac{1 mol}{32.0} = 0.875 mol S$

3) we divide the smallest value of moles (0.293) to each one.

Cu --> 0.876 / 0.293= 3
Fe---> 0.293 / 0.293= 1
S-----> 0.875 / 0.293= 3

4) let's write the empirical formula

Cu₃FeS₃

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Isotonic, hypertonic and hypotonic cells: describe

olya-2409 [2.1K]

<h3>♫ :::::::::::::::::::::::::::::: // Hello There ! // :::::::::::::::::::::::::::::: ♫</h3>

➷ An isotonic cell has the same concentration inside the cell as the outside solution. This would mean there is no net movement of water. Isotonic cells are sometimes called 'normal'

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Hypotonic cells are the opposite of hypertonic cells. They have a lower water concentration inside the cell than outside. This causes water to move into the cell and make the cell bloat.

[Any further queries, feel free to ask]

➶ Hope This Helps You!

➶ Good Luck (:

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4 years ago

If the sun rises at 7:36am and sets at 6:00pm, what times would we use for our data in the 24-hour clock format?

Dmitrij [34]

C is the answer I used to work at McDonald’s I know military time

6 0

3 years ago

Explain why materials with metallic lattice structures can be used to make wires and connections that conduct electricity in ele

kogti [31]

All metals have similar properties BUT, there can be wide variations in melting point, boiling point, density, electrical conductivity and physical strength.To explain the physical properties of metals like iron or sodium we need a more sophisticated picture than a simple particle model of atoms all lined up in close packed rows and layers, though this picture is correctly described as another example of a giant lattice held together by metallic bonding.A giant metallic lattice – the crystal lattice of metals consists of ions (NOT atoms) surrounded by a 'sea of electrons' that form the giant lattice (2D diagram above right).The outer electrons (–) from the original metal atoms are free to move around between the positive metal ions formed (+).These 'free' or 'delocalised' electrons from the outer shell of the metal atoms are the 'electronic glue' holding the particles together.There is a strong electrical force of attraction between these free electrons (mobile electrons or 'sea' of delocalised electrons) (–) and the 'immobile' positive metal ions (+) that form the giant lattice and this is the metallic bond. The attractive force acts in all directions.Metallic bonding is not directional like covalent bonding, it is like ionic bonding in the sense that the force of attraction between the positive metal ions and the mobile electrons acts in every direction about the fixed (immobile) metal ions of the metal crystal lattice, but in ionic lattices none of the ions are mobile. a big difference between a metal bond and an ionic bond.Metals can become weakened when repeatedly stressed and strained.This can lead to faults developing in the metal structure called 'metal fatigue' or 'stress fractures'.If the metal fatigue is significant it can lead to the collapse of a metal structure.

7 0

3 years ago

1.72 moles of NOCI were placed in a 2.50 L reaction chamber

elena-14-01-66 [18.8K]

The equilibrium constant, Kc=0.026

<h3>Further explanation</h3>

Given

1.72 moles of NOCI

1.16 moles of NOCI remained

2.50 L reaction chamber

Reaction

2NOCI(g) = 2NO(g) + Cl2(g).

Required

the equilibrium constant, Kc

Solution

ICE method

2NOCI(g) = 2NO(g) + Cl2(g).

I 1.72

C 0.56 0.56 0.28

E 1.16 0.56 0.28

Molarity at equilibrium :

NOCl :

$\tt \dfrac{1.16}{2.5}=0.464$

NO :

$\tt \dfrac{0.56}{2.5}=0.224$

Cl2 :

$\tt \dfrac{0.28}{2.5}=0.112$

$\tt Kc=\dfrac{[NO]^2[Cl_2]}{[NOCl]^2}\\\\Kc=\dfrac{0.224^2\times 0.112}{0.464^2}=0.026$

4 0

3 years ago

Given the following balanced equation at 120°C: A(g) + B(g) ⇋ 2 C(g) + D(s)(a) At equilibrium a 4.0 liter container was found to

BlackZzzverrR [31]

Answer:

a) kc = 0,25

b) [A] = 0,41 M

c) [A] = 0,8 M

[B] =0,2 M

[C] = 0,2M

Explanation:

The equilibrium-constant expression is defined as the ratio of the concentration of products over concentration of reactants. Each concentration is raised to the power of their coefficient.

Also, pure solid and liquids are not included in the equilibrium-constant expression because they don't affect the concentration of chemicals in the equilibrium.

If global reaction is:

A(g) + B(g) ⇋ 2 C(g) + D(s)

The kc = $\frac{[C]^2}{[A][B]}$